Automatic weighing apparatus



May 25 1926. 1,585,835

P. DURAND AUTOMATIC WEIGHING APPARATUS Filed March 26, 1925 2 Sheets-Sheet 1 May 25,1925 1,585,835

P. DURAND AUTOMATIC WEIGHING APPARATUS Filed March 26, 1925 2 Sheets-Sheet 2 l ihgdi ill FHQE.

PATENT PAUL DUBAND, OF PARI$, FRANCE.

AUTOMATIC 'WEIGI-IT'NG APPARATUS.

Application filed March 26, 1925.

The present invention relates to improvements in semi-automatic weighing apparatus or scales, giving direct readings of the kind in which supplementary unit weight are put into or out of action by manually operated mechanism.

The present improvement consists in an automatic mechanism adapted to suitably operate a supplementary unit weight or weights as soon as the object to be weighed causes the weight indicating needle or pointer to move beyond thenormal course graduated on the dial. In short it brings into or withdraws from action the required weight to return the scales to a state of equilibrium and to keep the needle within the graduated portion of the dial.

The automatic mechanism, which is the object of this invention, while maintaining the well known precision'oi semi-automatic scales give them a greatly extended scale of weights with all the advantages of auto matic scales.

The annexed drawings represent, by way of example, one arrangement for carrying out the invention.

Fig. 1 shows the automatic arrangement applied to a semi-automatic scale, in which the supplementary unit weights are brought into action or withdrawn therefrom by means of cams moulded on a shaft.

Fig. 2 is a side view of part of the same apparatus.

Fig. 3 is a side elevation of the controlling arrangement for the motor driving the automatic mechanism.

Fig. 4: is an end elevation thereof, whilst Figs. 5 and 6 are views from opposite sides of a detail of said arrangement.

Fig. 1 shows the scales in the position of equilibrium, the trays 1 and 2 being empty. The pointer 3 is at zero on the graduated scale 1 and moves over the scale to the position 3 when a weight corresponding to the unit adopted for the scales is placed onthe tray 1, but the needle can go beyond these two points and proceed on the one hand as far as 3 it the weight placed on the tray 1 is greater than the said unit, or on the other hand as far as 3 if the supplementary unit weight or weights placed on the tray -2 are greater than the weight deposited on the tray 1. The positions 3 and 3 correspond to the points when the respective trays are in their lowest position, and are in contact with. the frame or base of the scales,

fieiial No. 18,455.

The supplementary weights are controlled from a shaft 5 (Figures 1 and 2) provided with cams 6 acting on the weights 7 through the intermediary of rollers 8 and hooks 9 guided in bearings 10.- The cams 6 are conveniently arranged so as to cause one of the weights to be lowered and placed upon the tray 2 for each quarter of a turn of the shaft 5.

In the position shown, none of the supplementary weights is resting on the tray 2, but it a quarter of a revolution is given to the shaft 5 in the direction or the arrow at one weight will be deposited for a further quarter of a revolution a second weight will also be deposited, and at the end of three quarters of a revolution the third weight will be deposited and at the same time the abutment 11 attached to the shaft 5 will stri re against the stop 12 arranged on the frame of the scales. On the contrary for each quarter of a revolution given to the shaft 5 in the direction of the arrow 6 one of the weights 7 will be raised from the tray the abutment 11 coming into contact with the other side of the stop 12, as shown in Fig. 1, when the last weight is raised.

The shaft 5 instead of being operated, as is usual, by means of a handle (shown at 13 in Figure 2) is according to the invention connected to an electric motor 1 1 by means of a toothed wheel 15, chain 16 and a small toothed pinion 17, (Fig. 2) the ratio of trans mission being 1 to 4, i. e. each revolution of the motor causes the shaft to turn through a quarter of a revolution, that is to say, to deposit or raise one supplementary weight. The motor 14E carries at the end of its shat-t opposite to that to which the pinion 17 is attached, a small cam-disc 18 which operates the motor controlling mechanism which will be more fully described. This mechanism is made to operate in one direc ion by an electro-magnet 19 whose energizing circuit is controlled by a contact 20 (Fig. 1} and in the other direction by an electro-magnet 19 whose energizing circuit is controlled by a contact 20. The contacts 20 and 20 are situated. under the extensions of the trays 1 1 and 2, and their respective circuits are notclosed until the tray has moved sufiiciently to displaced the needle 3 beyond the graduated portion of the sector at.

Thus, when the tray 1 is charged with a weight greater than that of the unit on the scale pan 2 is moves the needlebeyond the same time gizing the causes one supplem ntary weight to be deposited upon the tray it the t weight so deposited is sui'licient to re estahlisii equilihrinm, the action oi the tray 1 upon the contact switch it ce ses ii'i'nnediately, but it not the circuit remains closed and the m tor revolves until a second weight is deposited upon the tray 2. It these two weights are not snllicient to restore e: i librium, the action continues automatic; for the third and last weight, but at tille moment, the shaft F, throu 'h the intermedi ary of the abutment l'n'eahs the circuit by opening the satiety contact switch 21 which is normally in closed position.

in this way, it the third weight is not suflicicnt to reestablish equilibriui the circuit closed by the switch 20 is opened by the switch 21 in orc or not to leave the motor energized, the scales having reached their maximum capacity.

On the contrary if after having deposited on the tray 1 a greater weight than that of the unit and having also deposited automatically sullicient supplement '3? weights on the tray?) to raise such weight or it, upon lightening the amount on the tray 1 to such a degree that the pointer 3 passes to the left (it the zero marl: oi the graduation, the

will close the circuit through the contact switch 2t and the GltCtlO-illzlgficft 19 will start the motor in the direction of the arrow 7) and one of the weights will. be lined, the operation being automatically repeated until such time as the pointer is brought to rest within the graduated zone of the sector t.

ii 7 count qwi 1c is race I t't t l p dii c cu t wni clectro-magnet 19 and contact:

i .5 1 in oroer to open the circuit when all the SllD lOlIlOllttiIf. weights ha e bcen raised.

will. be clear therefore that he scales c int. he influenced by any oscillations of 1c pointer wi hin the limits indicatet on the graduated scale, and the scales ti icrc V 1 rve all their precision while for gre l weigl s the operation oi? the sup iilomentary weights o iatie without thenecessity for any intervention on the part of the operator,

J of the the electromagnet 7 ch wn 1i ce ted lines lever 23 11s lever is at shaft 2" to whicn is 5 ts rainat ng in a s be? r 1e camec on the d sel rent lever 23 i r :e movement of the nose 26 towards r, and at the same time closes the contact swi ch 29 which completes circuit of the motor and causes it to revolve in the lircctiou indicated by the arrow a. The ihe eiectro-magnet 19 operates in a similar in anncr, the lever 23, arm Qel, lever 21') and projection F26, which latter oscillates bewcen cam surt'aces 27 and 28 formed on he other side oi the disc 18. It also acts, the intermediary of the lever 23 on the contact switch which closes the second motor circuit and causes the motor to revolve in the direction of the arrow Z).

The lever 2 and 2?) are in addition flexibly connected l means ot a plate spring so housed in a slot in the lever 23 and SllCling freel in a slot in a stud 81 fixed to the lever 23. in this manner the levers 23 l 23 both move together on a movement. the projection towards the stud 26, 'or example causing the projection 26 to nove towards the stud 26" in order to allow e we 16 to revolve in the direction a.

ll nen the cam-disc 18 has turned through nearly a revolution in the direction a, the cam sin-ta e 28 returns the projection 26 and the lever to their original posit-ions while the lever 2-3 opens the circuit at 29, the projection 26 abuts against the cam 27 and stops the motor at the end 01 exactly one revolution. If this one revolution is not sullicient to restore the equilibrium of the scales and the elcctro-magnet 19 is again energized, the action of the lever 23 causes the motor to make a further revolution.

On the other hand, when the circuit rough the switch 20 is closed to energize A romagnct 1i the operation is one exactly similar manner to cause to revolve in the direction of the in an t 1e i'notor arrow 5.

it, is evident that the arrangements dcscribedv above can be varied in a large measure without a'll'ecting the characteristics oi invention.

ll hat l claim is 1. ll eighing apparatus comprising a I pan an indicating pointer connein therewith and moving over a graduated scale a secondary pan connected to said weighing pan, a lever connecting the two pans,automatic means for depositing weights on said secondary pan, an auton'iatie motor pted to operat said automatic means and h electromagnetic switch in circuit with said electric motor adapted to be operated y increment of one of said pans, and open ates. directly by the pan support,

snpporto respectively for causing movement of said motor 1110116 direct on or he other.

3. \Veighing apparatus comprising a Weighing pan, an indicating pointer connected therewith and moving over a graduated scale, a secondary pan connected to said Weighing pan. circuit closing contacts cooperating with said pans and electro-inagnetic means energized through said contacts, a lever controlled by the armature of said clectro-inagnet, a cam-disc mounted on a motor shaft and co-operating with said lever to control the extent of rotation of said motor, and contact springs operated by said armature to start said motor to deposit or remove Weights on or from said secondary pan.

t. Veighing apparatus comprising a weighing pan, an indicating pointer connected therewith and moving over a graduated scale, a secondary pan connected to said Weighing pan, circuit closing contacts cooperating with said pans and electro-inagnetic means energized through said contacts, a lever controlled by the armature of said electro-magnet, acam disc mounted on a motor shaft and c0-0perating with said lever to control the extent of rotation of said motor, and contact springs operated by said armature to start said motor cam driven by said motor and means controlled by said cams for raising or lowering Weights from or on said secondary pan.

In testimony whereof I affix my signature.

PAUL DURAND. 

